THE ENTERIC JUICE. 



the divided gut are in either case united with each other and the 

 abdominal wound closed. 



In animals which have thus been operated it is noted that after 

 five hours following the ingestion of food a copious secretion of 

 fluid takes place in the small intestine, which continues for about 

 six hours. During this period of activity the mucous membrane 

 presents a rose-red color, while it is pale when at rest. As in the 

 case of the pancreas, the secretion is intermittent. It can be mani- 

 festly excited in a reflex manner, as a moderate secretion may be 

 observed within an hour after the ingestion of food that is, at a 

 time when but little chyme has passed into the small intestine. 

 Later, when the food has passed the stomach, its presence alone or 

 that of the digestive products which have been formed already, 

 apparently excites the increased secretion which is then observed. 

 This may be further increased artificially by mechanical and espe- 

 cially by electrical stimulation, and it is indeed possible to cause the 

 secretion of enteric juice in this manner even at a time when diges- 

 tion is not going on. 



In the upper portion of the duodenum of the dog the secretion is 

 said to be small in amount, mucoid, and jelly-like, while further on 

 it becomes more fluid. 



The enteric juice always contains a not inconsiderable amount of 

 mucus, which is derived from the goblet-cells that are found along 

 the entire length of the intestinal canal. The small amorphous flakes 

 which are always found in the secretion consist entirely of mucus. 

 The juice itself, which can be separated from the greater portion of 

 the mucus by filtration, is in the lower portion of the small intestine 

 a thin light yellowish fluid, of a strongly alkaline reaction. This is 

 largely due to the presence of considerable amounts of sodium car- 

 bonate, and we accordingly find that on the addition of an acid 

 effervescence occurs. Sodium chloride also is present in notable 

 quantities. The specific gravity in the dog is fairly constant, and 

 corresponds to about 1.010-1.011. 



The amount of solids is largely dependent upon the character and 

 the quantity of the food ingested, and in the dog may vary between 

 12.2 and 24.1 pro mille. These variations are mainly referable to 

 the presence of albumins, which are always found in the enteric 

 juice, while the inorganic constituents are fairly constant. A 

 general idea of the chemical composition of the secretion may be 

 formed from the accompanying analyses : 



Dog Horse 



(Thiry). (Colin). 



Water 97.59 per cent. 98.10 per cent. 



Solids 2.41 " 



Albumins 0.80 " 



Other organic matter (mucin) . 0.73 " 



Mineral ash 0.88 " 



Sodium carbonate .... 0.40 " 



Sodium chloride . . 0.48 " 



1.90 

 0.45 

 1.45 



